/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.core.io.buffer;

/**
 * Extension of {@link DataBuffer} that allows for buffer that share a memory
 * pool. Introduces methods for reference counting.
 *
 * @author Arjen Poutsma
 * @since 5.0
 */
public interface PooledDataBuffer extends DataBuffer {

    /**
     * Return {@code true} if this buffer is allocated; {@code false} if it has been deallocated.
     *
     * @since 5.1
     */
    boolean isAllocated();

    /**
     * Increase the reference count for this buffer by one.
     *
     * @return this buffer
     */
    PooledDataBuffer retain();

    /**
     * Decrease the reference count for this buffer by one, and deallocate it
     * once the count reaches zero.
     *
     * @return {@code true} if the buffer was deallocated; {@code false} otherwise.
     */
    boolean release();

}
